A passion for motoring is about much more than metal. Sure, if your daily mode of transport happens to be a glorified biscuit tin with an engine that's a revamped washing machine motor, it's easy to see why you might disparage those who feel passionate about cars.
You certainly couldn't contemplate spending €160,000 on something that will lose value every time it's tyres touch tarmac.
To these people, the idea of looking forward to every mile clocked up seems positively insane. They would not even begin to comprehend how a trip to the local newsagents could turn into a 40-mile trek. Or how an errand into Dublin could end up with a detour to Drogheda, Duleek, Ratoath and even over to Mullingar.
Yet get behind the wheel of a car like the M6, hit the starter button and listen to the hypnotic rasp of the engine, flick the accelerator and feel the surge. Suddenly all that passion starts to make sense. That's the magic worked by the uber engineers at BMW's M Division.
These are the people who can turn an already impressive driving machine into something bordering on a religious experience. They are the progenitors of the M5; in all its generational guises, arguably the greatest saloon car ever built in the last few decades. So what they do with the 6-Series was always going to be something special.
The 6-Series has always been a head turner, and in 645Ci guise, it's never been short of punch. So the M people - the German engineering boffins and not the Mancunian house band of the 1990s - set about adding their engineering wizardry to a car that was aesthetically worthy of their work. The M power brings it into a new stratosphere.
The power source is the same as its 5-Series sibling. It seems like a no-brainer that BMW should take the power of its fabulous V10 engine - along with the technological accoutrements - and pop it into the sleek 6-Series. This is a naturally aspirated 5-litre engine that redlines at over 8,200rpm and puts out over 507bhp at full tilt.
It's matched to BMW's seven-speed SMG gearbox. There has been some criticism that BMW offers too many options to the system, allowing 11 different settings for the gearbox, for example. Then there are three settings for the dampers and even an adjustment to the power output of the engine.
Leaving the iDrive and on-board computer to its own devices, you can simply call up the various functions using the four buttons surrounding the gear selector. The power button calls up the extra power from the engine. The EDC button changes the dampers while the last button simply controls the sensitivity of the gear changes.
At any time, hit the power button next to the gear selector and another 100 horses come on stream. That little button effectively adds on the equivalent output of a 1.6-litre VW Golf to the 400 bhp already on tap. If that doesn't impress you, then how about the fact the M6 also comes with a 'launch control' system that offers a take-off from standing start worthy of Fernando Alonso.
With all this praise does it seem that the M people can do no wrong?
Well there is the fuel economy, which averaged 13.2mpg during our week with the car. It's not helped by the 70-litre fuel tank, which meant we were an almost daily visitor to the local filling station.
Then there is the SMG gearbox. It's not that the seven-speed box isn't up to the task of transferring all that power to the wheels. Put to the test in proper circumstances it's excellent.
On an earlier run with the car on the Ascari race track in Spain late last year, the SMG gearbox and the glorious V10 brought us up to 100km/h in the requisite 4.6 seconds, on to the regulated 255km/h limit and then passed it, with the digital heads-up display showing 271km/h and the rev counter still some distance away from the redlines.
Our gripe with the SMG gearbox occurs when pottering around in town traffic. Even in the supposedly 'relaxed' setting in automatic mode, the changes are lurching as the car works its way up from second - from which it starts out in this setting - to fifth.
For our taste, the SMG works best when controlled via the manual shift paddles. We found the car behaves far better in all instances with the power turned up and the gearchanges at their most sensitive. That's when it feels most alive, most alert and nimble. In its other guises it feels like someone's drugged the horses under the bonnet. The M6 is clearly targeted at the likes of the Porsche 911 and while the latter is more tightly packaged and less influenced by the wealth of gadgetry on board the BMW, when the heaven's open, the M6 steers a steady course.
As a devotee of the Porsche badge, it borders on infidelity to fall for the allure of the M6, yet that's what happened during our week's sojourn with the BMW.
Yet, perhaps the greatest challenge it faces comes not from outside rivals, but within the Bavarian camp. For all its allure, we'd still opt for the M5.
The M6 engineers will quickly rattle off well-learnt lines about a lower centre of gravity and less weight thanks to the carbon roof. Both are technically true, even if the weight difference between M5 and M6 is only 45kgs, the size of a budding teenager.
The decision really comes down to image. The M5 can quite ably take on Aston Martins, Porsche 911s and Maseratis if it wants to.
The only problem with the M5 - for some, though certainly not for us - is that it's dressed up in family attire. For all the performance elements, some buyers want it not only to beat the 911 and Maserati on the road, but also to turn as many heads as the other two at the car park. That's where the M6 comes in.
With this new version you get M5 performance and 6-Series appeal. It's the best of both worlds then, so long as you don't need the practicality of a proper back row of seats.
The M5 is a relatively unassuming car for people who wanted to get home very quickly and enjoyably without making a song and dance about it. The M6 is for those who want a little song and dance along the way.
It's a matter of personal choice. The M6 is gorgeous and one of the few cars on the road these days that has other drivers drooling on their steering wheels at traffic lights. It's also addictive to drive. Yet if it were our money, we'd save €30,000 and opt for the Jekyll and Hyde character of the M5.
